Perforating guns for use in oil and gas wells traversing earth formations are well known. Early development of perforating guns included a bullet gun which shoots a projectile through the well casing, the cement sheath and into the earth formation. The subsequently developed shaped charge perforator generates a high velocity jet of energy which perforates a casing and cement sheath to produce a penetration in the earth formations. Chemical and liquid penetrating devices, as well as mechanical devices, have also been developed for producing perforations into the casing and earth formations. In the advent of modern production techniques, perforating guns which pass through a tubing and are operable in the casing below the end of the tubing also have been developed. In the latter type of gun it is usual to locate the gun to one side of the well bore and, if possible, direct the penetrating jet into the casing adjacent to the gun at a zero phase orientation. Other shaped charge perforating guns typically are oriented to produce penetration at an angle of 90.degree. or 120.degree. from one another and are symmetrically arranged.
While there are many variations of angular phasing of the penetrating devices illustrated in the prior art, there had been no suggestion that the phasing of the directions of penetrating devices can be critical or beneficial. Heretofore, the angular phasing in patents has been a matter of random illustration rather than choice.